That may be true in isolated cases but I don't think that wide-scale adoption of these technologies is some form of mass hysteria. I think it is because they solve real problems. I am not really a fan of the modern JS ecosystem for a variety of reasons but building stuff in React seems infinitely easier to me than writing plain HTML/CSS. I'm sure if you cut your teeth writing HTML/CSS (I didn't, have mostly been a backend developer) then you don't need to fancy new tools, but I hear an echo of "why does anyone need a garbage collector?" or "why use C when you can just write in assembler?" in these sorts of comments.